Add libtiff backend

1 files changed, 236 insertions, 0 deletions

diff --git a/src/backend_libtiff.c b/src/backend_libtiff.c
new file mode 100644
index 0000000..fcfdc7f
--- /dev/null
+++ b/src/backend_libtiff.c
@@ -0,0 +1,236 @@
+#include "backend_libtiff.h"
+#include "backend.h"
+#include "source.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/mman.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#ifdef IMV_BACKEND_LIBTIFF
+
+#include <tiffio.h>
+
+struct private {
+  TIFF *tiff;
+  void *data;
+  size_t pos, len;
+};
+
+static tsize_t mem_read(thandle_t data, tdata_t buffer, tsize_t len)
+{
+  struct private *private = (struct private*)data;
+  memcpy(buffer, (char*)private->data + private->pos, len);
+  private->pos += len;
+  return len;
+}
+
+static tsize_t mem_write(thandle_t data, tdata_t buffer, tsize_t len)
+{
+  struct private *private = (struct private*)data;
+  memcpy((char*)private->data + private->pos, buffer, len);
+  private->pos += len;
+  return len;
+}
+
+static int mem_close(thandle_t data)
+{
+  (void)data;
+  return 0;
+}
+
+static toff_t mem_seek(thandle_t data, toff_t pos, int whence)
+{
+  struct private *private = (struct private*)data;
+  if (whence == SEEK_SET) {
+    private->pos = pos;
+  } else if (whence == SEEK_CUR) {
+    private->pos += pos;
+  } else if (whence == SEEK_END) {
+    private->pos = private->len + pos;
+  } else {
+    return -1;
+  }
+  return private->pos;
+}
+
+static toff_t mem_size(thandle_t data)
+{
+  struct private *private = (struct private*)data;
+  return private->len;
+}
+
+static void source_free(struct imv_source *src)
+{
+  free(src->name);
+  src->name = NULL;
+
+  struct private *private = src->private;
+  TIFFClose(private->tiff);
+  private->tiff = NULL;
+
+  free(src->private);
+  src->private = NULL;
+
+  free(src);
+}
+
+static struct imv_bitmap *to_imv_bitmap(int width, int height, void *bitmap)
+{
+  struct imv_bitmap *bmp = malloc(sizeof(struct imv_bitmap));
+  bmp->width = width;
+  bmp->height = height;
+  bmp->format = IMV_ABGR;
+  bmp->data = bitmap;
+  return bmp;
+}
+
+static void report_error(struct imv_source *src)
+{
+  if (!src->callback) {
+    fprintf(stderr, "imv_source(%s) has no callback configured. "
+                    "Discarding error.\n", src->name);
+    return;
+  }
+
+  struct imv_source_message msg;
+  msg.source = src;
+  msg.user_data = src->user_data;
+  msg.bitmap = NULL;
+  msg.error = "Internal error";
+
+  src->callback(&msg);
+}
+
+static void send_bitmap(struct imv_source *src, void *bitmap)
+{
+  if (!src->callback) {
+    fprintf(stderr, "imv_source(%s) has no callback configured. "
+                    "Discarding result.\n", src->name);
+    return;
+  }
+
+  struct imv_source_message msg;
+  msg.source = src;
+  msg.user_data = src->user_data;
+  msg.bitmap = to_imv_bitmap(src->width, src->height, bitmap);
+  msg.frametime = 0;
+  msg.error = NULL;
+
+  src->callback(&msg);
+}
+
+static void load_image(struct imv_source *src)
+{
+  struct private *private = src->private;
+
+  /* libtiff suggests using their own allocation routines to support systems
+   * with segmented memory. I have no desire to support that, so I'm just
+   * going to use vanilla malloc/free. Systems where that isn't acceptable
+   * don't have upstream support from imv.
+   */
+  void *bitmap = malloc(src->height * src->width * 4);
+  int rcode = TIFFReadRGBAImageOriented(private->tiff, src->width, src->height,
+      bitmap, ORIENTATION_TOPLEFT, 0);
+
+  /* 1 = success, unlike the rest of *nix */
+  if (rcode == 1) {
+    send_bitmap(src, bitmap);
+  } else {
+    free(bitmap);
+    report_error(src);
+    return;
+  }
+}
+
+static enum backend_result open_path(const char *path, struct imv_source **src)
+{
+  struct private private;
+
+  private.tiff = TIFFOpen(path, "r");
+  if (!private.tiff) {
+    /* Header is read, so no BAD_PATH check here */
+    return BACKEND_UNSUPPORTED;
+  }
+
+  unsigned int width, height;
+  TIFFGetField(private.tiff, TIFFTAG_IMAGEWIDTH, &width);
+  TIFFGetField(private.tiff, TIFFTAG_IMAGELENGTH, &height);
+
+  struct imv_source *source = calloc(1, sizeof(struct imv_source));
+  source->name = strdup(path);
+  source->width = width;
+  source->height = height;
+  source->num_frames = 1;
+  source->next_frame = 1;
+  source->load_first_frame = &load_image;
+  source->load_next_frame = NULL;
+  source->free = &source_free;
+  source->callback = NULL;
+  source->user_data = NULL;
+  source->private = malloc(sizeof private);
+  memcpy(source->private, &private, sizeof private);
+
+  *src = source;
+  return BACKEND_SUCCESS;
+}
+
+static enum backend_result open_memory(void *data, size_t len, struct imv_source **src)
+{
+  struct private *private = malloc(sizeof(struct private));
+  private->data = data;
+  private->len = len;
+  private->pos = 0;
+  private->tiff = TIFFClientOpen("-", "rm", (thandle_t)private,
+      &mem_read, &mem_write, &mem_seek, &mem_close, &mem_size,
+      NULL, NULL);
+  if (!private->tiff) {
+    /* Header is read, so no BAD_PATH check here */
+    free(private);
+    return BACKEND_UNSUPPORTED;
+  }
+
+  unsigned int width, height;
+  TIFFGetField(private->tiff, TIFFTAG_IMAGEWIDTH, &width);
+  TIFFGetField(private->tiff, TIFFTAG_IMAGELENGTH, &height);
+
+  struct imv_source *source = calloc(1, sizeof(struct imv_source));
+  source->name = strdup("-");
+  source->width = width;
+  source->height = height;
+  source->num_frames = 1;
+  source->next_frame = 1;
+  source->load_first_frame = &load_image;
+  source->load_next_frame = NULL;
+  source->free = &source_free;
+  source->callback = NULL;
+  source->user_data = NULL;
+  source->private = private;
+
+  *src = source;
+  return BACKEND_SUCCESS;
+}
+
+const struct imv_backend libtiff_backend = {
+  .name = "libtiff",
+  .description = "The de-facto tiff library",
+  .website = "http://www.libtiff.org/",
+  .license = "MIT",
+  .open_path = &open_path,
+  .open_memory = &open_memory,
+};
+
+const struct imv_backend *imv_backend_libtiff(void)
+{
+  return &libtiff_backend;
+}
+
+#else
+
+const struct imv_backend *imv_backend_libtiff(void)
+{
+  return NULL;
+}
+
+#endif